Dark green vegetables seem to do quite well, as many are cold-tolerant and some even frost-tolerant. Kale is known for its cold-hardiness and its tolerance to freezing temperatures. In fact, some gardeners find that a touch of frost can improve the flavor of kale. This is due to an impressive bit of science: according to Constructor University, “At cold temperatures, the plant transforms complex carbohydrates in its cell walls into smaller sugar molecules.” While this quote refers specifically to kale, this has also been said of spinach and cabbage. That means, so long as the freezing temps don’t kill the plant out entirely, the colder the sweeter. As to which varieties look for, Winterbore or Redbor kale, Giant Winter spinach, and Tundra cabbage. 

Two less common leafy veggies you can plant in the winter are collard greens and chard. Collard greens and chard are both frost-tolerant, do quite well in the winter, and can add plenty of verdant color to the garden. Unfortunately, as lovely as the colors of rainbow chard are, you’re best off sticking with a white stem variety, per the Royal Horticultural Society, as these are heartier and have a better chance at survival while overwintering.

Source: housedigest.com